Dumping device for trucks



Sept. 5, 1939. B. G. HARLEY DUMPING DEVICE FOR TRUCKS 2 Sheets-Sheet 1 Filed Sept. 20, 1937 N Q\ m\ N IN v mom *N M. 0 Q l/III Y INVENTOR. f OA 6. law/4 1:7,

ATTORNEY.

Sept. 5, 1939. HARLEY 2,172,138

.DUMPING DEVICE FOR TRUCKS Filed Sept. 20, 1957 2 Sheets-Sheet 2 L I I INVENTOR/ BY 29 mww' ATTORNEY.

Patented Sept. 5,1939

DUMPING DEVICE FOR TRUCKS Berti-on G. Harley, Saco, Maine, assignor to Bertron G. Maine Barley and Edna B. Harley, Saco,

Application September 20, 1937, Serial No. 164,618

e Glaims. (ci. ate-22 This invention relates to dumping vehicles equipped with load dumping mechanism, and more particularly it relates to improvements in actuating mechanism for the tiltable vehicle body of motor trucks. I

A tilting mechanism of the type herein contemplated comprises a telescoping device or jack which operates under power normally derived from the vehicle engine.

7 l0 Ramm'ing'and cam action respectively are the two mechanical principles to be discerned in representatives of this class of mechanism. The load lifting leverage'inherent to a ram action device is found to be unfavorable orineflicient during the initial phase of the tilting operation owing to the unfavorable leverage or position of the ram relative to the body. The ramming action, however, becomes increasingly; effective as the angular movement of the body proceeds in S the act of dumping.

In the cam action device, conditions of relative efiectiveness are substantially the reverse of those in the ram type device, in that the cam action is particularly desirable during the initial 25 phase of tilting due to the great lifting power of its wedging efiect, although on the other hand I that efiectiveness drops off during the remainder of the tilting movement.

My object therefore is to design a tilting mech- 30 anism in which efiective operating leverages, lifting forces and stress reactions are established during all phases of the tilting operation, requiring a minimum of poweror hydraulic operating pressure for the lifting or dumping. Other 35 objects are to design atilting mechanism which can be readily adapted to existing or standard chassis and bodies.

- To this end I propose a design in which both the ram and the. cam action principle are com- 40 bined in such away that each becomes efiective during that portion of the tilting movement for which it is best suited. That is to say, I devise a mechanism which exercises cam or wedge action during'the initial phase of the tilting operation,

45. converting same into direct ramming efiect during the balance of the tilting movement.

According to one feature, while I obtain the benefit of ram action in the latter portion of the tilting movement, I do away with conven- 50 tional permanent pivotal connection between the ram and the box body by causing the ram at an intermediate point of the stroke to enter into temporary quasi-pivotal engagement with the box body. In distinction from ordinary ram 65 action devices therefore, the present constructime permits hoisting the body ofi the chassis by extraneous means for the purpose of inspecting the mechanism underneath, without necessitat-v ing the removal of a pivot connection normally found in ram devices between the ram head and l the body.

In a practical embodiment of my invention I arrange for a telescopic jack device to be mounted upon the truck chassis in such a manner that it .will start the tilting operation by direct wedging 10 or camming action forcing the body away from the chassis for an initial period. At a suitable intermediate point of the stroke the advancing head of the'jack will engage or be caught or intercepted in a hook shaped portion-on the rising body frame thus realizing a temporary quasi-pivotal connection between the'jack and the body, that is to say, automatically changing from camming to ramming action of the jack. device. The connection becomes self-securing during the balance of the tilting movement of the body to prevent overtilting of the body in the process of dumping.

Other features relate to constructions of a tilting mechanism, which make it readily adaptable to the structural conditions found in various types and sizes of chassis andvehicle bodies.

More particularly in one embodiment, ratio increasing linkage is interposed between the jack or ram rod or thrust member on the one hand, and the vehicle body and chassis on the other hand.-

In view of left-hand, as well as right-hand power takeofi requirements, the present .tilting mechanism is designed tobe mountable to meet either condition. A gear pump associated and substantially unitary with the hydrauliccylinder has features which also make it readily adaptable in that respect;

The invention is illustrated in the accompany- 4o ing drawings which show two embodiments of the invention for illustrative purposes, although it is of the best embodiment that Iknow of at present.

Fig. l is a diagrammatic side view of chassis and body in section and with the tilting mechanism and latch means therefor, in initial and final operating positions.

Fig. 2 shows an intermediate body lifting position of the mechanism of Fig. l, with quasipivotal connection about-to be established.

Fig. 3 is a diagrammatic plan view of Fig. 1, showing a combination of three cam rails with three cam rollers, efiective-between the chassis and the body, K a,

invention broadly by showing characteristic opv ious operating phases of the mechanism of Fig. 4. Fig. 1 illustrates the underlying idea of this crating positions in the procedure of tilting the truck body. Upon the supporting frame construction or chassis frame is a body H is pivotally mounted at B? for tilting movement. A body tilting or actuating mechanism generally comprises a hydraulic jack device, and an improved mechanism is herein shown to comprise an hydraulic jack cylinder or jack base member it extending substantially centrally and in the ldngitudinaldirection of the chassis, and it is pivotally mounted as at M upon the chassis by way of a transverse member it. A ram-rod it telescopes into and out of the jack cylinder and it is preferably, although not necessarily. hydraulic pressure-controlledto efiectits advancing and retracting operations. At its free end ram rod it is provided with a crosshead it or the like carrying a set of suitably arranged cam rollers such for example as a-set of three rollers including a pair of rollers it audit on the one hand, and a third roller 26 on the other hand (see Fig. 3). correspondingly the chassis frame id is provided with a pair of cam rails 25 and 22 straddling the chassis center line and having in clined cam faces Etc and 22a adapted to be engaged by the cam rollers 58 and id, whereas the body is provided with a third cam rail 23 arranged centrally with respect to the two other com rails and adapted to be engaged by the central cam roller A h 1: portion 26 is fixed upon the underside or the body it and shown to be associated with the third cam rail 23 and adapted to be engaged by the crosshead ill of the ram rod The operation of the mechanism so far described is suhstantially clear from Fig. 1, in which the body it is assumed to be loaded and at rest upon the chassis to as shown by its (full line) position A. At this time the swimrable jack cylinder is in the full line position shown in Fig. l,

' having its ram rod id withdrawn into the cylinder,

and its crosshead or cam roller end resting upon the lower portion oi the cam faces Zia and 22a oi cam rails 23 and 22. Tilting operation is started by supplying to the iwdraulic cylinder it hydraulic pressure as from an engine driven pump (not shown), causing the ram rod it to advance. Consequently the cam rollers, it, it and so will enter into pressure engagement with the cam faces or their respective cam rails 2!, 22 and 2t and thus through intrinsically powerful wedging efiect initiate the upward swinging movement of the body although under relatively low hydraulic pressure requirements. This wedging action maintains during the portion orhighest resistance of the tilting stroke and until the cam rollers have reached the end-portion of their respective cam rails or com zlaces when the free end or crosshead 6? of the rum rod it will be intercepted by the hook portion 26 upon the body.

At this t me, as the advancing ram rod it reaches a predetermined eflecti've end portion of its cain rails, the wedmngaction exercised upon the body will have been converted into straight ramming action inasmuch as the ram rod by way of the hook. portion 2 5 has then entered into a quasi-pivotal connection with the body'ii.

Therefore continued advance of the ram rod will finish the tilting movement oi the body until the latter reaches a predetermined end position B (shown in dot and dash) at an inclination which permits the load to slide ofi, thus permitting the body to unload itself.

It will thus be understood from the foregoing thatthe initial and heaviest resistance to load lifting is met according to this invention by powerful wedging action although requiring relatively low hydraulic operating pressure, while the diminishing load resistance during the continued upward movement of the body is met or sustained or overcome by direct ramming action.

Fig. 4 shows the tilting mechanism of Fig. l modified by the addition of ratio-increasing linkage, and thus rendered adaptable to a relatively greater variety of truck and body construction.

-The ratio-increasing linkage as shown in Fig. 4

comprises a swingable member Z'l pivoted at 28 upon the chassis frame 29, and a connecting link 3t between the free end of the swingable member 27 and the body iii. The swlngable member 21 is provided with'a hooked portion 32 for the purpose set forth in connection with Fig. l, and is otherwise efilciently shaped to sustain maximum bending stresses as shown. Otherwise, in Fig. 4 the jack device is collectively designated by the numeral 33 and includes the hydraulic cylinder 36 and the ram rod 335. A set of cam rollers collectively numbered 38 is provided on the free end or head 3? of the ram rod, which rollers are adapted to operatively engage upon stationary cam rails or members at fixed upon the chassis, and upon a corresponding movable cam member as represented by the swingable member 21.

The operation and ratio-increasing efiect of the modified construction is substantially self explanatory from the showing of Fig. 4.

I claim:

1. In combination with a vehicle having a frame construction and a body pivotally mounted thereon and adapted to m moved from position of rest upon the frame construction to load dumping upwardly tilted position and vice versa; an actuating mechanism for tilting the body, which comprises a jack device or expansible braceoperative between the body and the frame construction, having a base member pivotally mounted upon the frame construction and an advanceabie and returnable thrust member telescoping with said base member and adapted to tilt said body when influenced in its relation to the base member, and further comprising suitably arranged cam portions provided upon said frame construction and upon said body respec tively, to be engaged by said thrust member to force the body away from said frame construction during an initial phase of the body tilting movement, a hookportion associated with the body and adapted to receive and intercept the advancing hwd portion of said thrust member at an intermediate point of its body tilting stroke 7 oi the hook member about its quasi-pivot during the said balance or the tilting movement.

' 3. In a vehicle having. a'irame construction and a body plvotally mounted with respect there- 7 6 portion of said thrust member at an intermedito and adapted to be moved from a position of rest upon the frame construction to upwardly tilted position and vice versa, an actuating mechanism for tilting the body, which comprises a jack device operative between the body and the frame construction and having a base member pivotallymounted upon the chassis and an advanceable and returnable thrust member operated from said-base member and adapted to tilt said body, said mechanism further comprising a wedgellke cam portion mounted with respect to said frame construction and a companion wedgelike cam element serving as a track and pivotally movable with respect to the frame construction and effective incident to its pivotal movement to tilt said body, namely, when forced away from the first mentioned cam portion, both said cam portion-and said companion cam element designed and disposed to be engaged by said thrust member in a manner to force the body away from said frame ,construction during an initial phase of the body tilting movement, a hook portion associated with said cam element and adapted to receive and intercept the head ate point of its advancing movement, and further adapted to establish a temporary quasipivotal connection therewith and thereby to enable said thrust member to continue lifting said body by way of pivotal association therewith.

4. Mechanism. according'to claim 3, in which the companion element comprises a swingable member having its one end piv'oted with respectto the frame construction and itsother end movably connected with the body.

5. Mechanism according to claim 3, in which the companion cam element constitutes a memher in 'a chain of ratio increasing means operatively extending between the frame construction and the body. is v 6. Mechanism according to claim 3, in which the companion cam element comprises a swingable member having its one end pivoted with respect to the frame construction,- with the addition of a link pivoted to the other end of saidswingable member and to the tiltable body respectively.

BER'I'RON G. HARLEY. 

